What are the side effects of the Moderna vaccine?

side effects of the Moderna vaccine
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Here we list some of the most common and uncommon side effects of the Moderna vaccine and discuss the latest trials on pediatric participants

Recently the US pharmaceutical company, Moderna, announced that it will begin testing its COVID-19 vaccine on children aged 6 months to 11 years old. It is the first manufacturer in the US to test its vaccine on infants.

Currently, the vaccine should not be administered to those under the age of 18 due to the unknown side effects.

But what side effects can the rest of the population expect if they are immunised?

Common side effects

The vaccine will be given to you as two 0.5 mL injections and it is recommended that the second dose be administered 28 days after the first.

According to the Medicines and Healthcare products Regulatory Agency around 1 in 10 people can expect to experience very common side effects such as:

  • Tenderness and swelling of the injection site and underarm glands
  • Headache
  • Nausea
  • Vomiting
  • Muscle ache/joint aches/ stiffness
  • Fatigue (tiredness)
  • Chills/ Fever
  • Rash

As with most medicines, mild side effects like those listed above can occur and are not a cause for concern but if you are worried about any side effects you can report it directly to the Coronavirus Yellow Card reporting site. 

Uncommon side effects

Some of the more uncommon/rare or unknown side effects that may still occur include:

  • Temporary one-sided facial drooping (Bell’s palsy)
  • Swelling of the face (It should be noted that swelling of the face can occur in patients who have had facial cosmetic injections.)
  • Severe allergic reactions (anaphylaxis)
  • Hypersensitivity

How effects is the Moderna vaccine?

During clinical trials, the company announced that the vaccine proved to be 94.1% effective and has also shown to work on the South African variant. 

Moderna ingredients

The active substance in each dose is 0.10 mg mRNA encoding the pre-fusion stabilized Spike glycoprotein of SARS-CoV-2 embedded in lipid nanoparticles. It also contains polyethylene glycol/macrogol (PEG) as part of PEG2000-DMG and is a multidose vial which contains 10 doses of 0.5 mL.

Other ingredients listed include:

  • Lipid SM-102, cholesterol
  • 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC)
  • 1,2-Dimyristoyl-rac-glycero-3-methoxypolyethylene glycol-2000 (PEG2000-DMG)
  • Trometamol (tris)
  • Trometamol hydrochloride (tris HCl)
  • Acetic acid
  • Sodium acetate trihydrate
  • Sucrose
  • Water for injections

If you know you are allergic to any of the ingredients listed above then you should not have this particular vaccine.

You should also consult your doctor first if you have a weakened immune system, have a bleeding problem or have a high fever or severe infection.

Moderna expects to deliver its first vaccines to the UK in April.

Contributor Profile


  1. I’ve had a low grade fever starting 24 hours after receiving the first shot, 3 weeks since I tested positive with the virus. It’s day 4 of low grade fever. Normal?

  2. I’m one month out from my first Moderna shot and have been experiencing a range of neurological effects on and off since then – extreme dizziness, tinnitus, nerve shocks, heart palpitations, and muscle spasms. I’ve connected with dozens of other people who are experiencing the same (or worse) and we’ve been largely unable to find medical support. I am not an anti-vaxxer, but we deserve acknowledgment, treatment, and safer vaccines.

    • So have I and it’s frustrating. I can’t complete a full day without falling asleep numerous times in the middle of tasks

    • Omg I’m having the same, I thought I was going crazy. My worst is my eyes I’m getting like dizzy ziggy lines in my eyes and it was freaking me out and being dizzy. I had my jab 15 days ago still feeling weird. And got a rash on my arm

    • hmm same here heart palpitations .. along with every single symptom of heart attack. I went to the ER 4 times in about an 9 day period and all they talk about is anxiety. Which is not even in my vocabulary. There needs to be a trained team at every ER to deal with vaccine reactions. Were being written off like were just some kind of hypochondriac. This is criminal. I am now an anti vaccine person because of this. Never again.

    • I have had the tinnitus, skin is tingling and burning lastly my blood pressure increased 24-72 hrs after getting the vaccine. I was in the ER for it where I was being monitored . I was discharged with an Adverse reaction to the vaccine, and have not been told not to get the second dose . I dont like not seeing these reactions anywhere else

      • Since vaccination in April 2021, I experience leg calf pain constantly and feet tingling at times. MRI and X-ray lumbar shows nothing. The hospital rejected the cause due to Moderna. I am at a lost with no one to go to.

        • I’ve experienced leg cramps since my first dose. Frequently feel like I’m going to get cramp and occasionally do, mainly at night. I woke up last night because of cramp in my calf. This has only been since my first Moderna vaccine, never had problem with cramp previously.

    • I am now 2 months after my first moderna shot and still getting muscle spasms in my feet, abdomen, armpits, side of my head, back and other random places, though they far less frequent than the first few days after the shot. Have had chest pain the past month and a half and palpitations, though the latter have subsided. All tests came back negative for inflammation. Has anyone found treatment for the muscle twitches/spasms?

  3. I had a side effect, after the first shot, involving restricted breathing, not really breathing difficulty. Felt like when you have bronchitis and can’t take a full breath. Lasted until the second shot. After second injection this has reappeared. Not all the time but occasionally. Pressure in upper chest concerned my PCP, so he did an EKG, compared it to previous EKG’s and determined it wasn’t heart related.

    • I am going through a similar experience. I never suffered of asthma and I developed it 4 days after my first shot of Moderna. I suffered another very bad asthma attack 4 weeks after my first vaccine. I was lucky that the attack happened just on the eve of the due date for my second vaccine. I don’t even want to think how stronger side effects would have been with a second dose! I would be interested to hear of similar experiences.

    • Hi my niece has the same breathing problem after her first Moderna shot and she is wondering if she should get a second shot.
      Did it improve by now?

    • I also had a similar experience. Trouble taking a deep breath for more than an hour, nearly two weeks after my second shot. So scary that while I’m someone who never goes to the doctor or a hospital, I was wishing there was one nearby in case I needed oxygen. It was terrifying. Why aren’t these symptoms on the list of side effects?

  4. I had both Moderna shots and I didn’t get COVID!

    Someone needs to acknowledge that when you get these shots, you won’t get COVID! I think the government is not being very transparent about the fact that two of these shots keep you from getting COVID!

    We need the truth to be exposed! These shots stop COVID!!

    • Actually as we are hearing now, they are not preventing people from getting covid and some fully vaccinated have died, very few, but many have gotten Covid or the delta variant after both injections. However, I do feel that symptoms, I would hope, if you did get covid would be less severe. So if Covid symptoms are less severe and keeps you from going to the hospital, it’s a win win for most. Not everyone will have the same experience so I do think getting vaccinated is a personal choice. It’s too soon to say whether any of these people will fully recover from their symptoms and to live the rest of your life disabled in any way is terrifying, but it is early so I’m hopeful by the one year mark we will have more info and all of these people with symptoms will be 100 percent back to normal.

    • This isn’t true. I know ppl who have them and caught covid still. The vaccines help prevent you from dying but you can still get covid and spread it to others…you just might not get as ill or die from it is all.

  5. It’s been three days since I got the first shot, I awoke this morning to the room spinning out of control, so badly, I won’t drive.
    I too have been feeling like I’m having problems breathing and coughing uncontrollably, It feels like I can’t take a full breath, like when you have Bronchitis, not sure if I should consult my doctor or not?

    • Barbara, Please go to the Dr. The same thing happened to me with the first shot. they gave me antibiotics and steroids. it helped with the inflammation. the second shot not as bad but I have an upper resp infection and have 10 day antibiotics again. They told me people that had gotten covid and then do the shots will have it worse. the symptoms when you had covid you will get back with every shot. They were right.

    • How’d you make out! I’ve been in hospital 3 times now since mine with the breathing issue. They told me it’s anxiety. I know that’s not true. I have anxiety right now because I can’t breathe. Dr just did a d-diner blood test to check for blood clots.. hope you’re ok Barbara.

      • Hi Jojo,
        I’ve had the same problem. Been unable to breathe for 5 weeks now, in and out of hospital, it’s been complete torture. Ct scan shows abnormalities on my lungs. Have you had any success in getting better? I’m scared it’s never going to go away. This came on about 10 days after 1st moderna vaccine.

  6. Only on the arm I had my first vaccination which was several months ago. Started out with chills and then the red blotch would go down my arm, disappear or fade and then appear again. That has stopped, but now, especially at night, my left arm at the place of injection and underneath my arm, down to my hand, I experience strong aches, nerve shocks, and the pain pulses. I can’t figure out why, except for the possibility of a reaction from my first shot. Am I the only one experiencing this?

    • This happened to me the third day after my first shot and I’m three months past my second and this under arm aching and inflammation / tightness is still present I’m not sure what to do.

  7. I am wondering if the Moderna vaccine has an adverse effect of hair loss after both doses are completed. I had actual c Ovid in Dec. 2020 and was told to expect reactions to vaccines bugbear loss wasn’t mentioned. Thanks, Peggy Linder

    • Hi Peggy.

      I also lost basically all of the head on my hair, starting two days after my first shot.
      Over the next two months I lost nearly all of it until I had to shave the rest off.

      So far,no explanation and no intention to take the 2nd shot.

      Any improvement for you?

      Not much sign of it coming back, here.

      • I also started to losing scalp hair two days after the first Moderna shot. I had the second shot because I’d rather be bald than dead. Only now, seven months later, has the hair loss slowed and I’m starting to feel new hair growth along my scalp.

        If I need a booster, and believe I will, I’m going with Pfizer. Both vaccines are mRNA vaccines but the fillers cold differ. Once bitten, twice shy.

      • Same thing happened to my daughter. 24 years old. Healthy, long thick blond hair. 95% fell out. Shaved the rest. Heartbreaking.

    • Yes, me too! I got Moderna e.o. Feb and e.o. March 2021. I had covid 6 months before that, so the usual symptoms were minor to none after the shots. It was a few days after the 1st shot that my thin, fine hair started going AWOL. At times it slows down, as a teaser, then dumps clumps. The remaining strands are not as strong, so no clips, barettes, etc. can be used to cover the bald spots to avoid sunburn.

    • I am losing my hair rapidly, to the point where I discovered a small bold spot under my hair! It’s been a month since my second shot. I don’t understand why MEDIA DOES NOT COVER IT! People are losing hair. I’d better risk having covid than be bold (unlike the other person mentioned – personal preference and I respect everyone’s choices, I just didn’t have the chance to chose!). My heart is sympathizing with the mom of the young girl who lost all her beautiful hair – I hope it is only temporary! I am trying all the remedies I can.

      • I, too started loosing my hair in “alopecia” form about a week after my first dose. The fall out seems to have finally slowed down 7 months later. I ended up shaving my shoulder length dark brown hair… now all the regrowth is coming back in “white and very fine” – lately after reaching about 1″ long some of this new hair has started falling out. I reported this adverse affect to the CDC back in March. I went ahead and had the second dose, since the hair had already fallen out, but won’t be getting a booster.

        • I forgot to mention that I started experiencing problems with my hearing – (like my ears were stopped up) in late July – went to my doctor who removed an enormous amount of ear wax from both ears (I’ve never had issues with ear wax in my 66 years) – I asked if it could be because I most likely lost all the hair in my ears (that move the wax out) and he agreed it could be – this was later confirmed by an audiologist…

    • I had my Moderna shots in the spring and have noticed since then that my hair has thinned out considerably, I’d say about 20%. No other huge stresses this year other than normal daily life . Not sure if it’s from being vaxxed but don’t know what else would cause it. Health has been consistent.

  8. I took the Pfizer vaccine. I received my second dose on March 25 and I have been experiencing ringing in my head for several weeks with a rise in my blood pressure. Now I have to go to the ENT doctor. The ringing won’t stop.

  9. After the first shot in my right arm the only side effects I had was very sore pain in the injection site for about a week. When I got the 2nd shot I decided to take it in my left arm and now I wish I would have just gotten the one. I suffered severe headaches and shaking uncontrollably at times and very fatigued, I slept approximately 14 hours and was very tired after that for 6 more hours. And of course I had soreness in the injection site for another week. Boy am I’m glad that’s over.

  10. I’ve had some pins and needles feelings in my arms and fingers and sometimes legs. A strange tightness in the chest that is hard to explain. Also, a mild sore throat and headache. These symptoms had me worried, but I read that they’re relatively common with the Pfizer vaccine. Haven’t read as much about Moderna.

    • Exact same here. Tingling on my left arm, hand and leg (3 days after injection). Hoping it doesn’t last too long.

  11. I had the moderna vaccine and after my second dose I was out on blood pressure meds for elevated blood pressure. Never had a problem before. Read red pine tea is helpful but haven’t tried it yet!

  12. Hi, I am from the Uk and following approx 2 wks of numb fingers and palpitations I unfortunately suffered a Stroke. I am 45. No problems previously and it would appear there are no issues 1 wk on???
    I have never experienced any issues previously. No weight issues, smoking etc
    I would be very keen to reach out to anyone with similar problems.
    Cheers Paul

  13. Had my first Moderna vaccine in January. Came home from work exhausted. Eleven hours after the shot I rolled over in bed and had pain in my right hip. An hour later tried to get out of bed due to the worst cramp from the hip down to my foot with an additional camp on the outer side of my calf. My husband tried muscle rubs. I took muscle relaxer, ibuprofen, and another pain pill. Nothing worked. The next day was started on prednisone and gabapentin by one of my doctors. Slept in recliner most nights on a heating pad with automatic off timer. As the cramp continued it felt like the nerve going down from my hip to my foot was being strangled. By the third day I lost feeling in my great toe and some of the bottom of my foot and the skin on top of my foot going up from my great toe. Also have a numb spot on the side of my calf where it was cramped. Had second vaccine and had shooting electric shock pain in right great toe. Was really annoying for 36 hours-this is a reported symptom- but I figured The feeling might come back, it didn’t. The doctors say that these are not typical symptoms that are listed as side effects of the vaccine so my regular doctor referred me to PT. Went to physical therapy- made what little decrease in pain I had come roaring back. Also by this time I realized and showed my therapist that I can’t lift the toes on my right foot at all, unlike my left. Physical therapist said to get MRI and doctor finally ordered it after doing Neuro check after I told him I can’t lift my toes. He also realized I have weakness in both feet. MRI is not that bad per doctor. On the night of May 6, almost 4 months after my vaccine I had a far worse back, hip, leg and foot muscle spasm event at night and despite meds, massage and heat I couldn’t stand up. I had to crawl to the bathroom as I was unable to put weight on my right side. I was able to do a walk-in visit at my chiropractor- had started seeing him 1 week after the first spasm. By the next day I was in a wheelchair- thank God for my church having one. I saw my MD on the following Monday(in wheelchair) and got stronger meds and was given three weeks off of work. I was in a wheelchair for 8-10 days. I am now getting injections from pain management and regular visits from the chiropractor. I now walk with a cane and thanks to that muscle spasm, I now have lost feeling in the next two toes. It is now June. From my first shot I was enrolled in V-safe and they send regular text messages to me and I filled them out about my back, hip, leg, and foot. They called two weeks ago and spoke with my husband and asked him to have me fill out an Adverse Event form. We finally were able to talk last week and she said she read my report and blieves it is vaccine related due to the most timing and some of the other reports now coming in.They are with the CDC. The lady and I talked and she said to continue to report to them and that my events will be posted. She was so helpful and made me feel like I’m not crazy. So even if your symptoms aren’t listed, tell your doctor and the V-safe people and the CDC. Hopefully soon, my pain will resolve with chiropractic care, pain managent, and meds. I will
    never take a booster of this shot.

  14. Same here.. I can not do to much for fear of having a heart attack. I walk up the stairs or just walk fast and my heart races. It palpitates and I get extreme fatigue. Pericarditis is what my symptoms resemble yet no ekg or any blood work shows any sign of this. Strange how this all happens..

  15. Helpful to see these comments. I had my first moderna shot, im a healthy 27 y/o female, but have had breathing problems got the 4 weeks since. I went to hospital and they said nothing came up on ECG. Back to doctors again but again said heart rate and oxygen levels are fine despite clear struggles to get a decent breathe. I’m worried as weather to get second dose or not, doctors says yes but also says we don’t what would happen. Doesn’t fill me with hope. Did anyone have breathing issues then have the 2nd dose, what happened?

  16. I also have been losing a lot of hair since I had the Moderna vaccine. I am hoping there is another explanation. Has anybody had any luck in stopping the hair loss?

    • Same here. My father and grandfather have excellent hair and have never had problem with hairloss in their entire life and my hair was thick and healthy until I got a moderna shot. My hair started thinning and it didnt take long for me to notice the baldness happening near my forehead. Extremely frustrated.

    • I also had a lot of hair loss and finally went to my dermatologist who started me on treatments. It is much better now and starting to see new hair growth. Very scary do not want anymore vaccines

  17. I have been losing my hair as well!!my first shot was Pfizer and no problems but since my Moderna my drain is full everyday my combs are full luckily I have lots of hair but when does it stop!!!I also have been so sleepy!

  18. I had my first shot in May and was okay other than a swollen arm, had my second shot 4 weeks ago and have not been the same. I had the usual standard side effects (chills, body aches etc) for 24 hours and then started to feel better. 48 hours later I couldn’t swallow, my throat was swollen, tight chest, daily anxiety attacks even when I don’t particularly feel anxious. I also have severe acid reflux which just seems to be getting worse. My GP makes me feel like I am being dramatic and is putting it down to anxiety but I know it isn’t, really frustrating.

  19. Just wondering if Moderna can alter levels of Immunoglobulin levels and also affecting a metabolic profiling.

    Good to have a Infectious specialist comment on this.

    • I have had a lot of hair loss as well. It’s stressful and sad. I thought it was because the modern vaccine made my menstrual cycle and hormones go all wacky.

  20. Had Moderna shot fully vaccinated in February. My hair loss is so bad its like I’m on Chemotherapy! I literally wash my hair & its coming out in clumps so much that its scary. Its been 8 months and it still hasnt stopped falling out. Like this is shedding this is clump after clump. I started wearing a wig thinking so I wouldnt put heat or comb or friction or anything on it. & it is still the exact thing lumps of hair so I now no its not anything im doing externally its what was injected internally into my body. Like put a disclaimer be honest give validate peoples reactions!

  21. For those asking about hair loss, I had my 2nd covid shot in early Feb. The end of March I noticed a clump of hair missing from the base of my scalp. I have no idea how long it was there due to the location. Obviously I freaked out and went to dermatology, was diagnosed with alopecia areata and prescribed topical steroids. I had blood work done and everything on that end was fine. I told the doc that I had a feeling it was from the vaccine, but at that time she said she hadnt heard anything regarding that being a side effect. I still knew it was from the vaccine and no one could tell me differently! Anyway, i did the topical steroid for a month and then steroid injections 1x a month for 3 months. Happy to report that my hair is growing back! My heart goes out to everyone dealing with this! It really is so traumatic. If you havent yet, try reaching out to dermatology and good luck!

    • Hi Paula. I have been on the topical steroid for a month now. I follow up with my dermatologist in a few weeks, I think i’m going to ask about the steroid injections. Did the injection stop the shedding or just help with new growth??

  22. I had my first Moderna vaccine on 4/22/21. Shortly after I found myself finding it hard to talk and slurred speech. Since the onset I’ve stared to have neurological symptoms such as spasms in my arms and legs, weakness in my left arm mostly, By 2:00 or 3:00 I’m spent, I come home from work and go to bed. I feel cloudy in my thoughts and overwhelmed easily. I also find myself having a hard time holding in my emotions. I burst into tears for seemingly no reason. MRI, bloodwork, EMG/NCV and urine testing have revealed NOTHING so far. What I’m experiencing could be completely unrelated to the vaccine but I find it odd that they can’t find anything wrong with me and before the vaccine I was completely fine.

  23. I had both Moderna shots…i started to notice a difference in the texture of my hair..and definitely thinning near my forehead.. I thought maybe I was bring hypochondriac..but relieved when I read other people are experiencing this issue..I’m calling my primary on Monday..so I can get a referral to be seen by a dermatologist!!

  24. Omg..I too got this falling hair badly…please help!! Got my first dose last aug 31 2021..my second dose is on sept 28…but hair kept on falling really…

  25. I showered and washed my hair before getting the Moderna shot. The following day I did not wash my hair. The next day after I did and brushing my hair found a round patch of hair missing on the top of my head. I haven’t been able to look at my whole head, but have been able to find one other circular bald patch in the back. The front of my hairline is receding more daily. For some reason the left side of my head the hair is falling out more. I use a large soft brush and there are clumps of hair I have to clean out of it daily. My hair has been long almost down to my butt with no split ends…. And now it’s falling out. I’m supposed to get my second shot soon and don’t know what to do.

    Is anyone else’s scalp easily irritated? If I run a brush through it parts of it turn red.

    I’m wearing a bandana each day to cover it. I might be vain but I LOVED my hair and took a lot of pride in it. Now brush fulls are leaving. The pharmacists I have talked to say they have never heard of this side effect. Why is this not public knowledge?

  26. My husband received the Moderna shot and 10 days later he had crippling pain in his left hip down to and in his knee, he couldn’t walk straight up for weeks, he had to walk bent over. The pain was excruciating no matter if he stood, sat, laid down. After 6 weeks it is starting to ease up but the morning are still the worse. We are hoping this will eventually go away for good.

  27. Hello – my wife is 62 and received the 2nd Moderna shot in April 2021. She started noticing hair loss in June and it has continued through the summer. She has just started injections and topical treatment. Hopefully that will support regrowth. She has had a couple episodes of alopecia areata in the past. But this is much more severe than previous episodes. I believe it is a reaction to the vaccine and it is due to her autoimmune issues (she has eczema and asthma). It would be good for this to be verified as a side effect so that dermatologists are aware of this issue.


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